.\" Copyright (C) 1993 David Metcalfe (david@prism.demon.co.uk) .\" .\" Permission is granted to make and distribute verbatim copies of this .\" manual provided the copyright notice and this permission notice are .\" preserved on all copies. .\" .\" Permission is granted to copy and distribute modified versions of this .\" manual under the conditions for verbatim copying, provided that the .\" entire resulting derived work is distributed under the terms of a .\" permission notice identical to this one. .\" .\" Since the Linux kernel and libraries are constantly changing, this .\" manual page may be incorrect or out-of-date. The author(s) assume no .\" responsibility for errors or omissions, or for damages resulting from .\" the use of the information contained herein. The author(s) may not .\" have taken the same level of care in the production of this manual, .\" which is licensed free of charge, as they might when working .\" professionally. .\" .\" Formatted or processed versions of this manual, if unaccompanied by .\" the source, must acknowledge the copyright and authors of this work. .\" .\" References consulted: .\" Linux libc source code .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) .\" 386BSD man pages .\" Modified Sat Jul 24 18:05:30 1993 by Rik Faith .\" Modified Fri Feb 16 14:25:17 1996 by Andries Brouwer .\" Modified Sun Jul 21 20:55:44 1996 by Andries Brouwer .\" Modified Mon Oct 15 21:16:25 2001 by John Levon .\" Modified Tue Oct 16 00:04:43 2001 by Andries Brouwer .\" Modified Fri Jun 20 03:04:30 2003 by Andries Brouwer .\" .TH STRERROR 3 2001-10-16 "" "Linux Programmer's Manual" .SH NAME strerror, strerror_r \- return string describing error code .SH SYNOPSIS .nf .B #include .sp .BI "char *strerror(int " errnum ); .br .BI "int strerror_r(int " errnum ", char *" buf ", size_t " n ); .fi .SH DESCRIPTION The \fBstrerror()\fP function returns a string describing the error code passed in the argument \fIerrnum\fP, possibly using the LC_MESSAGES part of the current locale to select the appropriate language. This string must not be modified by the application, but may be modified by a subsequent call to \fBperror()\fP or \fBstrerror()\fP. No library function will modify this string. The \fBstrerror_r()\fP function is similar to \fBstrerror()\fP, but is thread safe. It returns the string in the user-supplied buffer .I buf of length .IR n . .SH "RETURN VALUE" The \fBstrerror()\fP function returns the appropriate error description string, or an unknown error message if the error code is unknown. The value of \fIerrno\fP is not changed for a successful call, and is set to a nonzero value upon error. The \fBstrerror_r()\fP function returns 0 on success and \-1 on failure, setting \fIerrno\fP. .SH ERRORS .TP .B EINVAL The value of .I errnum is not a valid error number. .TP .B ERANGE Insufficient storage was supplied to contain the error description string. .SH "CONFORMING TO" SVID 3, POSIX, BSD 4.3, ISO/IEC 9899:1990 (C89). .br .BR strerror_r() with prototype as given above is specified by SUSv3, and was in use under Digital Unix and HP Unix. An incompatible function, with prototype .sp .BI "char *strerror_r(int " errnum ", char *" buf ", size_t " n ); .sp is a GNU extension used by glibc (since 2.0), and must be regarded as obsolete in view of SUSv3. The GNU version may, but need not, use the user-supplied buffer. If it does, the result may be truncated in case the supplied buffer is too small. The result is always NUL-terminated. .SH "SEE ALSO" .BR errno (3), .BR perror (3), .BR strsignal (3)